From: "Eric" <eddot1103a@mindspring.com>

Date: June 22, 2006 8:25:37 PM MDT

To: <Astro_IIDC@yahoogroups.com>

Subject: Re: [Astro_IIDC] Jupiter through my 6" refractor

Thanks, Alan.  It may be Schuler IR-78 that passes from 780 nm on.  I had used their UV pass filter to bring out some Venutian features last year.

Eric   

----- Original Message -----

From: Alan Friedman

To: Astro_IIDC@yahoogroups.com

Sent: Thursday, June 22, 2006 11:15 AM

Subject: Re: [Astro_IIDC] Jupiter through my 6" refractor

Eric -

The IR pass filter I have is from Schuler - I don't remember the spectral response numbers. CCD chips are quite sensitive to IR - you will definitely notice the brightness increase as you move from R to IR. The RGB filters I have are an SBIG set purchased some years back - they do have IR blocking coatings.

Alan

On Jun 22, 2006, at 6:03 AM, Eric wrote:

Alan,

Just a couple of quick questions here- what brand of IR filter are you using?  I tried one on Jupiter myself last year and found much reduced gain over the RGB set, but I think it was definitely due to the brand/ frequency response I had used.  Also, is the R filter you use IR blocked or not? 

Thanks,

Eric